Männerbund, male solidarity between comrades in arms, has vital importance in war, at least in ancient warfare. In Homeric poetry we find clear examples of the importance of such ties, always between men, and observe a variety of possible overtones. Moreover, the bond that unites a couple as Achilles and Patroclus has an additional component, that of the friend as counsellor and confidant. The purpose of this paper is to analyze the role played by the pistos hetairos, the reliable friend, in the well-being of the warrior. The basis of this study will be the Iliad, epic in whose plot the couple Achilles-Patroclus is an excellent example of the positive function exercised by the existence of a friend, confidant and comrade absolutely faithful, as well as the dangers of that presence disappearing. Aside from the possibly erotic nature of the relationship between Achilles and Patroclus, the latter’s fundamental role is that of reliable counsellor to Achilles, the same role that Nestor plays in relation to Agamemnon, or Polydamas to Hector.